Lens



Aug. 31, 1943. A. a. DICKSON LENS 4 Sheets-Sheet l Filed June 17, 1941 I mm ATTORNEYS.

J. B. DICKSON 2,328,329

' LENS Filed June 17, 1941 4 Sheets-Sheet 2 A'ITORNEYS.

LENS

Filed June 17, 1941 4 Sheets-Sheet 3 INVENTOR :JOHN 5. mama/v M 44% ;v

ATTORNEYS.

Aug. 31, 1943. B. DICKSON LENS Filed June 17, 1941 4 Sheets-Sheet 4 QA. E..

INVENTOR c/OHN 5. D/C/(cS/V ATTORN EY the local axis of the lens.`

Patented Aug. 31, 1943 e "LENS e e i f JolnB, meksomn and Park; Mich., assignor i 3 y i to C rysler CorporatiomHighland Park, Mich., i i a corporation of Delaware e y y Application June 17, 1941, Serial No; 398,43 9 7 e presentinventieri relatestoa isor par ticula utility for stop"lights,directional signal cessory" lights, although the inVenti n maybe utilized injany field-whereinlenses may be of use.

i ;The lens is characterizedby having an outer "conflguration Ldictated by 'aesthetic considerations so that the body of the lens ;hay be asyrnmetrical with respect to its fcalaxis. This is particularly true in modern automobile manufacturing, since it is now accepted practice to design accessory ulenes soas to'carryoutsome artistic' therne, thus i presenting unusual shapes which the 'engineering stafimust lnternally design to cause the lenses to perform` the' light directlng Iu'ction's' considered i desh-able; A" further( problemthis createds en e countered` in the manufacturetof lenses since modem glassor plastiomolding processes tend to lights,` parkin'g' lights, orj other automobile ac- 9 oai s. (c. alo- 106.15

ordinary` shaping tools in the` hands' of relatively unskilled mechanics. i i i These and other objectsand advantages of the present invention 'will be more readily apparent from a study of the following spjecfication taken in connection with the accompanying' drawings wherein out.

followsf` e 4 Fig. 1is &Li-ear elevation of a modificationof the invention showing the application of the present invention to a lens of substantialiy ectanguvlar shape in projection along the focalaxis there-` or. y

Fig. 2 is a front elevation of the lens' disclosed i in Fi 1.`

dictat ,the angular characteristicsvofprisms `or` r other internal .shapfes "which the engineers may use" to cause the lenses to have thedesirednlight transmitting characteristics.

An object of theprese'nt invention is to form a e lens having aii` outer surface of substantially any artistic shape with inwardly extending ridges or` other conflguratlons whereby a substantially large 'area ,of the lens prdjected upon `a plane normal 7 to the focal axis of the lens collimates light about ;It is well known in the artthat a lens e nploy--e ing a central bull's-eyetlensyor other central condensing surfa c`esm'ay be s'rrounded by cliopjor catadioptric lens f orrnationswhereby the collimating portion of a large lens may be extendecl beyond thev irnpleangle to which the condensing portion nayextend, l-lowever, such lenses are of symrretrical shape with respect to `'the focal axis of thelens and it has heretofore been' thought iripossible to apply the theories i :thereof to lensesot 'unusual or asymmetrlcal' shape. An object of the present invention isto providemeans or a` ;teaching whereby the major. proportion of lens maybe utilizedlor light collimating p pos e.` v 4 i A further object ofthe-present invention is to so 'torm lenses of asyinmetricalshape having` the !oregolngcharacteristics that the same 'may be manufactured bydie pressing methods of molding siass' or other plastics.`

A further objfectof the present invention isto provide lenseshaving the foregoing characteristics v which ;may-` `be `toi-med` by pressing dies including a malefdie having a surface configure.-

tionsuch as tubim the desired ridge's or other' 4 isurfaces, which male die may be 'fonned by Fig. 3 is, ahorizontal section takensubstan tially 'alongsline 3-`3 of Fig. 2, the" plane of 'they i section extending through the focal axis of the lens.` i

along line !Ia-4 of Fig. 2, the plane of the section being taken substantially through the tocal axis ofthelensv` h h 'f Fig. 5 is ayside elevation of a modified form 'of lens with'the present invention applied thereto;

,Fig. 6' is a plan view of the form of lens shown n Fi .&` i a 1 i Fig. 'lis a horizontal section taken through the focal axisvand substantially along line T 1 of Fig.5." e 1 Fig. 8 is' a'vertical section taken through the focal axis and ubstantially along line kam Fig.6. g A e V Fig. 9 is aside elevation of a furthermodiea tion.` v A j i Fig. 10 is a `front elevation ofthe modification shown in Fig. 9.

Fig.' 11 isa vertical sectlontaken through the `focal axis and substantially along line lI--l l 'of i Fig. 10.

`. "Fig. 12 is a horizontal section taken through the focal axis and ubstantially along the"`line `IZ---IZ of Fig. 11."

Fig. 13 is a side elevational view of a lens em# bodying a further 'development of the inven tion. a i 1 Fig. 14 is a top plan view of the lens shown-in Fig.13. t i

Fig. 15 is a horizontal section taken `on line l5-l5 of Fig. 13. a i I l Fig. 16 is a vertical section taken on line !li- 15 ofFig.15.

like numerals refer to like parts through In the accompanying drawings,` there are disclosed several modificatlons of the invention as i Fig. lis 'a vertical section takensubstantially i Four forms of lense embodying the present invention are thus illustrated in the drawings, but

it is to be appreciated that the forms shown are illustratve of a wide variety of lenses which may have the present invention 'applied thereto.

Referring particularly to Figs. l to 4, inclusiva there is disclosed a lens 20 of substantially rectangular Outline when viewed along the foc'al axis, the lateral dimensions thereof beinggreater than the vertical dimensions thereof. The lens comprises' a body portion' of asymmetrical shape I with respect to the focal axis and having an outer- I surface 2I which is substantially smooth but I shapedto Carry out the desires of the designer or artist. The inner surface 'of the lens is provided with a centra surface 22 arranged in dioptric tend the area of thelens which directs light along the focal axis, I provide a plurality of rid'ges acl- 'jacent the central section 22.

v Thiis, I provide a plurality of vertically extending substantially straightand parallel ridges 23'at each side of the,

agreement with the outer surface so as to provide 4 a bull's-eye condensing portion; In order to 'excentral section, .and a plurality of liorizlontally exi tending substantially straight, and parallel ridges above and below the centralsectionzz. The i ridges 23 and the. lowermost. ridge Mappearing in Fig. e have irwardly bowed or longitudina'llf convexed Vertces, shown in Figs. 3 and 4, from which diverge oppositev side faces. All portions of these ridge side faces toward the optica'l axis of the lens are adapted toreceivelight rays from the focus 3.7 As illustrated at theright in nga, such light rayare reflected .by the oppo's'ite ridge faces andarepassed through theilers in acourse .y

such'that they are collimated by the portions of thelens 'of unalterable contour through. which they pass and which register With these ridges.

,Allbutthe lowermost of the ridges 24 shownin 3 havevertices bowed inwardly of the lens from which divergeopposite sidefaces. All 'por tions'of these ridge side faces remote from the optical aXis of the lens are adapted 'to receive light rays from the focus S` and to direct such' light rays' through the lens in a course such that :they

surfaces are mainly arranged in dioptric agreement with the outer surface ZI. Thu's, surfaces "lifi, 27 and 28 are arranged in" dioptric agreement with the portion of the outer surface adjacent thereto so as to cause collim'ation of light rays striking the surfaces. The other side of these particular ridges presentssurfaces which, for the purpose of die formation, are diverged from planes parane to the focal axis of 'the' lens. The angl'es of `divergence of these surfaces are as small v as possible in order that light rays falling within' -the angles A, B and C andlost by dispersion represent an irreducible minimum loss. As illusrated by the lowermost ridge 24 the configuration "cfthe lensmay besu'ch that a c'atadioptric prism would best serve, even though the lost rays falling within the angle D may be relatively large' at this particular point.

I have illustrated the lens as provided with vertical'flutes 33 formed in the outer surface thereof in orderto spread a small portion of the light laterally, These fiutes are a .relatively shallow so that the outer surfaceof the' .lensremains substantially smooth in' thersense that there are `no deep groove's" "orvsharplprojectionsto prevent cleaning of the lens. surface. It is .to be, appreciated that? the lens mayor may .not he pro'- vicledwith such fiutesfas desired, m invention having to do' with the internal constructioh where'- i by condensation of the light rays 'into abeam is accom'plished; f i

: In the form of the inventionillustratedin Figs 5 to 8, inclusive,` the' lens `bndy35 compris'esan outer surface 3B`of substantially straight; vertical elements presenting, a sharp; substantially para: bolic Outlineinhorizontalsection;` This lens may also be'jprovidedwith horizontal flutes 31 in order are collimated by the portion of the surface ofthe lens of unalterable `contour through which they pass and-with which these ridges register.`

" Although .the present linvention is particularly adapted for dioptric prisni formations, such as particularly illustrated in Fig. 4, it may he seen in; Fig. 3 that` certain' consideratiors, such asthe' relatively plane surface of thelens when viewed 'vertically as seen in Fig..3', may require the formationi of. catadioptric'prism surfaces. Thus,-th.e ridges 23" comprise catadioptric 'members having sides so arranged with respect to the unalterable outer surface that the maj or portion of the light rays emanating from thefocal point S is' collected and directed forwardly in substantialrparalielism with the focal axisof the central section 22. 'The ridges maypartially shade each other in'order that as much light as possible'may be int'ernally v refiected a seen with respect, to the rays 25;

Only a very small portiorofthe light', such as internal dispersion.

Asseen inFg'. 4: the lens when viewed in its vertical relationship presents such an irregular curve that doptric inner surfaces arebest utilized. Therefore, the ridges M are preferably provided with relatively large surf'aces facing the fo-cal axis of the lens, in the sense that .they. are iin di.- rect light receiving relation to light rays emanating from a source at the focal point 5.'. These i to spreadjjsom e"lightvertically. As seen'in 'hori zontalsection in Fig."7 'and in vertical 'section in riclgespresent toward theiocai :point relatively large surfa'ces 50' arranged in dioptric agreement with the unaiterable outer surface. In order that the ridges may 'be formed by a male plunger op eratingalong the focal axis of thelens, the sides ti; intercepting" light rays'within` the angle F, are also of 'relatively large -surface'area but pre sent'relatively small areas projected onto a plane normal to the focalaxis-'of the lens so that the those raysincluded in the angle ll, is thus lost by i light rays so'lost by' clispersi'on are reduced tea minimum The ridges 39, may be' provided with a central section 'of c'ne curvature in crest 'eleva tior', as'seen' Fig. 8, and tipportions 42 of an other curvature'in crest eievation so as wex tend the collecting area thereof as far as possible. As also seen in Fg. 8; the lensmay be' provided with a horizontally extending, substantially straight ridge a'adjacent' the central` section't; there ,being insuificient roomjform'ore than' one such ridge and, for that matter, the` surface M' above the central section %and the surface 45 below the 1 ridge is being naturallyin `clioptric agreement with the suiface 3'5. The ridge 43 pre- ?sent sa surface 46' ogflarge area in-dioptric agree;-` ment with the outersuriace sfi and a surface 41 tical axis of the lensas in Figsgli'and 12.

Additional emciency: is achievedby the provision oi ubstantially straight,- i parallel, v vertically exv tending 'ridgs 52 ateach side of the'` oentralsec-` tion, each of which presents a largedioptric sur-` face 53 toward theflfocal axis and has a surfalcel of arelatively small 'area in projection "normal to the focal a- XS Oi'thC lens through which light falling'within the angle Hjis dispersed. This form of lens may also `have'shallow flutes 55:ex`-

tending horizontallyabout thelens. i a

v Withlthe type of 'lens herein disclosed,'the

i amount 'of light projectedin a desired direction is so -increasedover the ordinary lens without ooptical configurations that it is no longer necessary to use auxilaryopticai parts such as re-` flectors and extra lenseswithin'the'lamp, with the result that the cost of the lamp is lconsiderably reduced without lossvin lightefliciency. 1 e\ t In the form of the invention iliustrated in Figs. 13 to 16, inclusive, the `lens body'is provided with a central bull s-eye lens portion which, as in the previously described figures; is in v optical.

agreement with theportion of the outerlens surface'll wth which it registers. Disposed ad-` Jacent the bull's-eye lens portion 10 is a pairof 'substantially `vertically extending ridges 12 which i have surfaces arranged in dioptric agreement with those portions of the outer surface TI with which they register. Theridges 12 are similar in construction and function to the ridges 52` of Figs. and 12. Adjacent the dioptric i'idges 12 is a p series of ridges 13 substantially `parallel theretowhich have surfaces arranged in `catadioptric agreexnent with the portions of'the outer surface 'H with which they register. t e i v v With this combination ofoptical surfaces,` it is possible to collimate light tover the areaof lens e having a; wide spreadwithrrespect to itswfocal ;pointp i i i I Having illustrated and described several modiflcations embodying the present invention, it

should be apparent to those skilledin the art that-the principles herein disclosedmay be *applied to any lens having an unusual configu-aand a plurality of substantially straight, inwardly protruding ridges adjacent said collimating center, each of= said `ridges` having an apex bowed inwardly of` the lens body and a side face extending therefromzjxof substantially large area` disposedin light receiving relation tothe focal point of the lens and arran ged in'dioptric collimating agreement with `saidouter surface, whereby 'a i substantially" large portion of i the lens` collimates light ;about the .focal axis of the lens.

2. A ;lens comprising. a 7 body of asymnetrical shape with respect to its focalaxi's and having a substantially smooth outer surfac or unalterable configuration dictatedby'aesthetic consideratiohs;

the inner surface of said having a' central areasurrounding the focal ax-isof the `lens and arranged in dioptriclagreementwith' said outer and a plurality of substantially straight, inwardly w i surface to form therewitha'collim'ating; center.

protruding, parallelridgesadjacent said collir'nating center at the sides threof; each of` saidridges i having, a vertex-bowed inwardly of said lens body "toward the focal point thereof and aside extending therefrom of substantially large area disposed in light receiving relation tothe foca1 `point offlthe lens and arranged in dioptric agreement with said` outer surface, whereby a substartially large portion :of the lens area'projected onto'a planenorabout the focalaxis of thelens. i u

3. A lens com'prising a body vof asymnetrical mal to the `foce`l`axis` of the lens collimates light shap withfrespect to its focal axis and having a substantially'smooth outer surface of unalterable conguration dictated by aesthetic considerations,` theinnersurface 'of said body having a central g v areattsurroundingtthe focalQaxis of the lens and arranged ingdioptric agreennt with said outer surface to` 'form therewith a collimating center,

and apluralit'yof substantiallystraight, inwardly I protruding, parallel ridges adjacent said collimat ing center at the sides thereof, each of said ridges having a longitudinall'y `convexed Vertex and a side extending 'therefrom' of substantially large area disposed in light' receivingrelation to the focal point' of the lens' and `arrang'ed in` dioptric agreement with said outer surface, whereby a substantially large portion of thelens area projected onto ap plane normal 'to the focal axis of the lens collimates light about the focal axis of the lens;

the sides ofsaidridges being divergent from planes v parallel to the focal axis of the 'lens toward said g outer'surface `whereby said lens maybe forrned tion byvarying thenumber and optical characteristics of the ridges and by varyingthe surface configurations of the central 'portion and the ridges toprovide opticalagreement` thereof with the unalterable outer surface. All such modificatlonsas come within the scope of the following claims are considered to be part of my invention. i i

Iclaim:

1. A lens comprising a body of asymmetrical i shape with respect to its focal axis and havingua substantially smooth outer surface of unalterable configuration dictated by aesthetic considerations,

the inner surface of said body having arcentral areasurrounding the focalaxis of the lens and arranged in dioptric agreement with said outer surface to form therewith a ccllimating center,

by diesincludinga male die reciprocated along the focal axis 'of the'lens through the focal point thereof. f v n 4 A lens "comprising a `body of asymnetrical shape with respectto its focal axis and having a substantially s'mooth outer surface of unalterable configuration-dictatedby-aesthetic considerations,

the inner surface `of `said body having a central area 'surrounding the"`foca1 axis of the lensgand*` arran ged in dioptric agreeinent with said outer surface to form therewith acollimating center, a

plurality of substantially straight, inwardlyprotruding", parallel and vertical ridges adjacent said collimating center at the sides thereof,-` and at least one other substantially straight ridge adjacentsaid collimating center and running normal to said vertical ridges, each of said ridges having a longitudinally convexedvertex and a side of substantially large area disposed in light receiving relationto the focal point of the lens and arranged in dioptric agreement with said outer surface,

whereby a substantially large portion of the lens v area proJected onto a plane normal to the focal !mis :@I :the 'lens eollimates light about the recel axis cftheieiis I j 5 ..A lens comprismg a body" erasymmetrical shap'e with respect to its 'c'ca-laxis and haviii g a substantialiy smooth cut-er surface of unaltera'bl ;con-figuration dictatedzuby ncn optical coisiderations, a pluralitvcf lsubstantially straight ihward ly protrudingparallel i 'dge'sprojectihg ;in-

wardlyjf rom the ihner side of' said lene-each of said ridges having a*longitudirially ccrvexed ver tex and v cccperating` `'side faces extending therefrom ofgsubstantiallylarge area disposed inlight receivi rg rela'tion to the' t focal pint, of* 'the lena and arranged in catadioptri'c collimating agree ment With the portionsofsaid outer surfacewitl i v which it r egisters;-respectively,` wherebv substantially; large portion of; the' lensarea project'ed i onto a plane normal to th -roam 'axis of thelehs collimateslight ,abcut the `f'ocal axis of thelehs,

the `sides of said r idges. being divergent from planes parallel to the:fo"cal axis :of the ler 's 'teward said outer suhtacewhereby said l'ens maybe formed, by 'dies including 'a'fmale die reciprocated along the-fccalaxisof the lensthrcugh the fo'cal .pci nt therecf., 4 i i ;6. A lens ccmprising a bodyof asymm'e'tri'cal shape With respect to its focal aiis 'and having a substantially smccthouter surface of unalterable cohfiguration dictated ;by non opti'cal considera tions, the inner surfaceg 'cfjsaid body having a central area surrounding the focal axis of .the lers and arranged indi'optric `a'greement'With said.

` outersur face to form thereW-th a -collima'ting Cellter, ;a lplurality of substantially straight;.inwardly protruding, parallel andvertical r'idges adjacent "said collimating center at the; side's therecf, 'and a plurality of suhstantially straight," inwardiy protrud ing, parallel and horizontalridg'es ;adja'cent mansion, a plurality of substantially straight and they arecollim'ated'upiemergng frcmgsaid pore i .tichsofsaidsurface.

8. A lens' comprising' ahody ofa'symmetrical shape With respectto its focal axis having a relativelyslight curvature of comparatively long* radius in i one dimension and a 'substar'rtially `greater curvatur'e of comparatively shorter radius in a :dimension 'normal to said first mentioned diparallel catadi optric 'cellimating' ridges proj ecti ng in'wardly from 'said lensbody and extending in the ;direction of the greater curved dimenson'of the latter, eachof said catadioptric ridges having a 'Vertex bowed 'inwardly of 'said'lens body and cptically active coceerating sides'extendng therefr'om and dispo'sed in light 'recei'vng relation 'to the focal point of said lens and so constructed and arranged 'in 'catadioptric collimating agree ment 'with the portions' of said 'outer surface with which they register 'as to'dir'ect light rays emahal ing from said' focalpoint through-?said lens' ina coursesuch that they emerge from said 'outer surface porticns in collimated relaticmand a plusa-id collimating center, each of said 'riclge's having a vertexbo-Wed' inwardly of said lers body'and'a 'side face ertending therefrom disposed in light shape With respect to its focal axi's and having a substantially smooth outer surface of'unalter'a ble' z' cohfigurationdictated by non-optica1 consideratiene; aplurality of -substantially straight and parallel ridges protr-uding from :the inner side 'of saidlens, ;eachcf ;said ridges having alongitudirally cohvexed vertex and. a substanti'ally coni+ .i

cal side face extending the-ref-rcmofsubstantially large .area disposed in :light receivinge relation, to the focal point of the lens and'so c'onstr-ucted and arranged in dioptriccollimating agreement With respect to related portlons of said outer' surfocal point throughsaidlens ina course such that ralty of substantially straight and parallel'di- V optric collimating rdges project-,ing'inwardly from said -le'ns body and extehding ijr ;the direction of the less curved dimension of`the*l tter, each ef said dioptric ridges having a vertex 'bo wed inwardly of said' lens body and an c'ptically active side faceextendi'ng therefrom and disposed in light receiving relaticn with the focal point of said lens 'and so constructediahd arranged' in doptric ccl-limating' agreemen't with "the pc-rtons of theouter'surface Withwh'ich it registers as to direct lightrays enianating'from said focal point through said lens 'in a course such 'that they emerge from said'outer surface porticrs in collim'atedrehtion.

9. A lens comprising 'a body of asymmetrcal shape with respect toits fo'cal axis and having'a substantially smooth 'outer surface of unalterable configuration dictated by non-optical considerai tions, the inner surface of said body having a central area surrounding the focal axis of the len's and arranged in dioptric agreement With a portion of said outer surface With which it registers i to form 'therewith a 'collimating center, 'a pair of substantially straight, inwardly protruding; par'- allel ridges, one on each side of said collimating center and each projecting' invvardly from the inner side of said lens, each ofsaid ridges having a longitudihally'convexed Vertex and cooperating side faces extending therefrom of substantially large 'area disposed in light receiving relationto .the focal point of said. lens and arranged in cata dioptric collimating agreement With the portions of said outer surface with which it registers respectively, Whereby a substantially large portion of the lens area pr'ojected onto a plane normat to w the focal axis of the len's collmates light about 'face as to directight raysemanating from said v the focal axs of the lens.

` JOHN B. DICKSOM 

